An advisory group on vaccines established by the World Health Organization (WHO) is developing a framework to determine the appropriate strain composition of COVID-19 vaccines based on which SARS-CoV-2 variants of concern, such as Omicron, are circulating. That is why the group on Wednesday urged vaccine developers to gather data on the immune response of their vaccines against the SARS-CoV-2 variants of concern (VOCs).
To make a recommendation on changing the strain composition on COVID-19 vaccines, the group will consider “global spread and transmissibility, clinical severity, genetic, antigenic and phenotypic characteristics of the VOC, including capacity for immune escape and assessments of vaccine effectiveness,” the WHO said.
WHO had established the Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) in September 2021 to review and assess the public health implications of emerging SARS-CoV-2 variants of concern on the performance of COVID-19 vaccines and provide recommendations on the composition of COVID-19 vaccines.
The WHO said the work of this group complements other groups such as the Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE), the Strategic Advisory Group of Experts on Immunization (SAGE) and its Working Group on COVID-19 Vaccines, and the working groups of the WHO R&D Blueprint for Epidemics.
The TAG-CO-VAC said that future COVID-19 vaccine development priority should be given to “COVID-19 vaccines that have high impact on prevention of infection and transmission, in addition to the prevention of severe disease and death.”
The group added that “until such vaccines are available, and as the SARS-CoV-2 virus evolves, the composition of current COVID-19 vaccines may need to be updated to ensure that COVID-19 vaccines continue to provide WHO-recommended levels of protection against infection and disease by VOCsn, including Omicron and future variants.”
